The manufacture of an integral writing nib and ink reservoir is disclosed in my own U.S. Pat. Nos. 4,086,312, 4,104,781 and 4,119,756. However, in the method of the above patents the formation of the hard pen nib portion is performed by the step of dipping either or both ends of the pen material into liquid urethane prepolymer to impregnate urethane prepolymer into the fiber bundle portion and hardening the urethane prepolymer filled portion by the reaction of urethane prepolymer constituents after removal from the urethane prepolymer liquid.
However, when in this method the sign pen material is dipped into urethane prepolymer liquid the sheath portion is also dipped into liquid, which results in poor appearance and workability of the pen in the later finishing processes. Furthermore, this reduces considerably the rate at which the pens may be mass-produced in a continuous manner.